/*
 * JBoss, Home of Professional Open Source
 * Copyright 2005, JBoss Inc., and individual contributors as indicated
 * by the @authors tag. See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package com.ambow.util;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import com.ambow.studyflow.exception.AsfException;

public abstract class IoUtil {

	public static final int BUFFERSIZE = 4096;

	public static byte[] readBytes(InputStream inputStream) throws IOException {
		byte[] bytes = null;
		if (inputStream == null) {
			throw new AsfException("inputStream is null");
		}
		ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
		transfer(inputStream, outputStream);
		bytes = outputStream.toByteArray();
		outputStream.close();
		return bytes;
	}

	public static int transfer(InputStream in, OutputStream out)
			throws IOException {
		int total = 0;
		byte[] buffer = new byte[BUFFERSIZE];
		int bytesRead = in.read(buffer);
		while (bytesRead != -1) {
			out.write(buffer, 0, bytesRead);
			total += bytesRead;
			bytesRead = in.read(buffer);
		}
		return total;
	}
}
